Pluripotent cells can serve as sources of large numbers of differentiated cells, such as neurons and cardiac muscle. The number of candidate pluripotent cell lines is rapidly growing, and current methods for demonstrating pluripotence are technically difficult, so researchers, clinicians, and the NIH stem cell program have a great need for straightforward, reliable assays for pluripotence. We propose to develop a rapid, accessible, and easily interpretable assay to define pluripotence and to identify specific cell lines. PUBLIC HEALTH RELEVANCE: The technology we are developing would be useful in a wide variety of applications involving pluripotent cells. These include basic cell biology studies to understand the functioning of normal cells and disease mechanisms, toxicology and teratology, drug screening, and preclinical and clinical studies. In the longer term, pluripotent cells have the potential to be used in regenerative medicine, which will require reliable assays for pluripotence. [unreadable] [unreadable] [unreadable]